A flash memory used as a non-volatile memory stores data by storing or removing electrons from floating polysilicon or silicon nitride to change a threshold voltage Vth. Recently, a phase change memory (PRAM), a magnetic memory (MRAM) and the like have stored data by changing a resistance using externally applied heat or magnetic fields. Although research has been done on a resistive random access memory (ReRAM) using voltage to change the resistance of an oxide film, the development of the structure of the ReRAM has been insufficient.